1. Field of the Invention
The present invention relates to a retrieval device and method of retrieving audio signals recorded on a video floppy disk that is used as a recording medium for an electronic still video camera, etc.
2. Description of the Related Art
In such a video floppy disk, each of the tracks in which audio signals are recorded is usually divided into four sectors. The heading of the audio signals is executed, as disclosed in Japanese Unexamined Patent Publication No. HEI 1-269292, by demodulating audio signals recorded in the sector at the top of each track and sequentially outputting these signals as a voice.
Audio signals can be recorded and reproduced, respectively, in modes of about 5 seconds, about 10 seconds and about 20 seconds per track, respectively, according to the use of a compression ratio. As described above, as one track consists of four sectors, the recording and reproducing time per sector in each mode is about 1.2 seconds, about 2.5 seconds, and about 5 seconds, respectively.
However, when voices are recorded in, for example, the mode of about 5 seconds per track, the reproducing time is about 1.2 seconds, which is very short. Therefore, it is difficult to recognize the reproduced voices and a problem arises in that it becomes difficult to retrieve an appointed track. Conversely, if all of the audio signals are reproduced, it takes a lot of time, and the efficiency of the retrieval is worsened.